The use of lasers in dental procedures has been pursued for some time starting with experiments conducted with the first lasers developed in the early 1960's. Unfortunately, the lasers and wavelengths available were unable to effectively act on dental hard tissues without excessive heating resulting in pulpal necrosis (tissue death). Up to the present time, these experiments were conducted with Ruby, Helium Neon, and CO2 lasers. While the pulsed and CW CO2 lasers have been found to be effective in some ways on dental tissue, they suffer from the lack of a suitable optical conduit necessary for procedures inside the mouth.
Other uses of lasers in dental procedures are described in U.S. Pat. Nos. 4,273,535, 4,521,194, 3,821,510 and 4,784,135. In U.S. Pat. No. 4,273,535 a device is described using a NdYag laser at 1.06 microns wavelength for sealing tooth surfaces to prevent tooth decay. A flexible glass fiber is used to deliver the NdYag radiation to the tooth surface under treatment. Another application of the NdYag laser is disclosed in U.S. Pat. No. 4,521,194 where the radiation is used to remove incipient carious lesions and or stains from teeth using the output from a glass fiber directly without focussing optics or handpiece. Crystals of hydroxyapatite are fused to render the tooth surface impervious with the laser at 1-100 millijoules. A handpiece for delivery of focussed laser beams and fluids is described in U.S. Pat. No. 3,821,510. In particular, a flexible light transmitting fiber, fluid conduit and adjustable focusing system is described. U.S. Pat. No. 4,784,135 describes a Far Ultraviolet system for surgical and dental use and claims to use a non-thermal ablation mechanism. In a preferred aspect of that invention, a laser having a wavelength below 200 nm is used to treat decayed teeth by a photodecomposition action.
A significant problem in the prior art is that the action of the laser beams on the dental tissues does not disclose the capability to cut enamel surfaces with a device that is practical for use in the dental clinical environment. The only known device described with the potential to cut enamel is the Far ultraviolet laser which has significant disadvantages due to the operational characteristics of the excimer lasers employed as well as limitations on transmission through optical fibers. Accordingly, it is a primary object of this invention to provide an apparatus and method for safe and efficient cutting, drilling and fusion of dental tissues without damaging adjacent living tissues.
It is another object of this invention to provide a technique for cutting, drilling, and fusion of dental tissues in a practical system that can be utilized in the dental treatment environment.
Another object of this invention is to provide a technique for sealing or fusing the surface of dental hard tissues, including root surfaces.
It is still another object of this invention to provide means for the fusion of artificially produced coatings to the surfaces of teeth.
It is a further object of this invention to provide a means of removing unwanted hard deposits of foreign material, such as calculus and plaque deposits, from the surface of dental tissues.
It is another object of this invention to provide for the cutting, and drilling of dental bone tissues in the preparation of implant sites.
It is yet another object of the present invention to provide an apparatus for dental treatment with a laser which can be aimed with an aiming reticle co-aligned to the laser beam.
Finally, it is another object of the present invention to provide a system for the selective removal of soft tissue, such as diseased gums by the action of the infrared radiation and to provide for the sterilization of gum pockets.